Melting pot for slug-casting machines



Jan. 12,)1932. G E MARLATT 1,840,517

MELTING POT FOR SLUG CASTING MACHINES Filed NOV. l1. 1929 Patented Jan. 12, 1932 PATENT FFIQE GEORGE E. MARLATTOF PASADENA, CALIFORNIA MEL'IING POT FOR kSLUGr-CAS'lINGr MACHINES .Applicationy led November 11, 1929. Serial No. 406,482.

My invention relates to slug-casting machines, and by way of example is illus rated as applied to machines of the linotype class. My improvements apply to the melting pots of such machines and the result sought is the production of better slugs. In present commercial machines the slugs produced are frequently objectionably porous as the result of an excessive amount of air being forced from the pot into the slug-forming mold in advance of the molten metal. The improvements herein disclosed are designed to exclude the air from the pot before the casting operation takes place. rllhe manner of attaining` this objective is illustrated in the accompanying drawings, in which- Figure 1 is a vertical section from front to rear through the mold and theimelting pot, as improved, of a. linotype machine, also showing the manner of supporting and the mechanism for actuating the pot;

Figure 2 shows the melting pot, as improved, in contact with the mold;

Figure 3 shows the rear surface of the potmouthpiece, as improved;

Figure l shows a modification of the improved pot-mouthpiece;

Figure 5 illustrates a modification;

Figure 6 illustrates a modification;

Figure 7 illustrates a modification.

In linotype machines the melting pot 1 is pivotally mounted on a shaft 2; prior to the action of the pump plunger 3 for forcing metal into the mold 4, the mold-carrier 5 is moved forward a short distance to place the mold in engagement with the matrix line 6; next the pot 1 is tilted forward by its cam 7 until the perforated mouthpiece 8 is in contact with the mold 4, whereupon the pump plunger 3 descends under control of the pump cam 9, forcing the molten metal into the mold slot 10 and against the matrix line 6, thus forming the printing slug. Heretofore the mouthpiece perforations 11 have been in line with and in direct continuation of the pot throat 12, therefore the molten metal could not be maintained at a level high enough to exclude air from the throat 12, for the reason that the metal would pour through the mouthpiece porforations as the pot tilts forward towards the mold. lis a result of 'this condition the air in the throat above the safe metal level is forced into the mold slot and mixes with thercast in the mold, causing the slugs to be more or less poro-us according to their varying size and other conditions; also the initial movement of the plunger is noneffective for filling the mold since a large quantity of molten metal must be raised in the throat 12 before the mold is filled.

ln order that tinJ molten metal may entirely lill the pot throat 12 without escaping after the pot is tilted and before the pump 3 descends, offset the pot throat 12 relative to the mouthpiece perforations 11, as shown in Figs. 1 and 2. Therefore the metal may ow forwardl and entirely fill the throat 12 when the pot is tilted forward against the mold in usual manner, but will not escape since its surface is below the perforations 11.

mold is limited to the slight amount which may be contained in the perforations 11 and the upper ends of the vertical grooves 13.

It is immaterial whether the ver ical grooves 13 are on the mouthpiece 8 3) or onthe pot Crucible as (15) i Fig. 5, or partly on both as (16) in F ig. 6; and in any one of these three arrangements individual grooves may be omitted anda continuous vertical passageway 17 may embrace all the perforations as shown in Fig. el, but in the latter arrangement a comparatively greater amount of air will enter the mold and there is more liability of the metal splashing into the perforations 11 when the pot is tilted toward the mold. This liability of the metal splashing into the perforations may be lessened by inclining the passagewa f (13) as shown in Fig. 7.

In order that the molten metal in the pot may be maintained at a sucient height to lill the throat 12 without the possibility of rising to the perforations 11 when the pot is tilted forward, l provide an overflow outlet 19 for the pot Crucible. This overflow outlet is preferable through vthe wall of the crucible 14 as shown in Fig. 1, and has secured thereto an extension 2O leading to a suitable receptacle 2l placed beneath the pot. The mouth 22 of the overflow outlet is located relative to a safe height for the molten metal, and any excess metal which may be fed to the pot will cause an overflow which will be received. by the receptacle beneath the pot. When the pot is tilted toward the mold the metal level recedes at the overflow mouth 22 and rises in the throat 12,-and'with the pot` normally full the initial movement of the plunger 3 will serve to fill'the mold'and any additional time allowed for the descent of the plunger will serve to holdthe pressure until the cast has chilled.

' The particular arrangements herein illustrated are merely by way of example, and modifications other than those described may be resorted to without departing fromthe spirit of the invention.

What l claim is:

l. .lnaslug-casting machine, a meltingy pot having a perforated mouthpiece and a throat leading thereto, the perforations in said mouthpiece being above said throat but in constant communie-ation therewith. y

2. In a slug-casting machine, a tiltable melting pot having a throat sealed by a mouthpiece capable of preventing` the flow of metal from said throat when said pot is tilted, a plunger for forcing the metal above thel liow level in said throat, perforations through said mouthpiece above saidf flow level, and a lateral passageway in direct con tinuation of said throatthrou-gh whichpas,

sageway metal may be forced from said throat to and through the said perforations by action of said plunger.

3. ln a .slug-.casting machine, in combination with a Crucible having a discharge throat substantially horizontal at the discharge end thereof, a perforated mouthpiece closing said discharge end, and a mold into which molten metal may be pumped from said throat through the perforations of said mouthpiece, means for preventing an excess of aii passing from said throat to said mold, said means being a substantially vertical upward offset-of said throat where the horizontal end thereof joins said mouthpiece, theA perfor-ations in said mouthpiece communicating directly with said offset.

4. A combination as specified in claim 3,v

characterized by the fact that the vertically offset portion of said throat is continuous to 6. A combination as speciliedlinclaini,

characterized by the fact' that-thevertically offset portion of said throat is formed in the wall of said crucible throat.

7. A combination as specified in claim 3, characterized by the fact that the vertically offset portion of said throat is formed in said perforated mouthpiece.

8. A combination as specified in claim 3, characterized by the fac-t thatthev vertically odset portion of said throat is formed partly in the wall of said Crucible throat and partly in:y said perforated mouthpiece.

9. In a slug-casting machine having a crucible, means for preventing an excess of molten nietalinnsaid Crucible, said means beingl a duct'coniined wit-hin a portion of the crucible wall, and extending. from top to bottom thereof with an opening into the interior of said Crucible, through which openingexcess molten metal'may flow and thence passv through said'duct and escape therefrom.

Signed at Pasadena,` Los Angeles county,-

California, this 15th day of4 July, 1929.l

GEORGEl E. MARLATT.

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